ASTM_G_92_-_86_2015.pdf

Designation:G9286(Reapproved 2015)Standard Practice forCharacterization of Atmospheric Test Sites1This standard is issued under the fixed designation G92;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice gives suggested procedures for the char-acterization of atmospheric test sites.Continuous characteriza-tion can provide corrosion data,environmental data,or bothwhich will signal changes in corrosivity of the atmosphericenvironment.This practice can also provide guidance forclassification of future test sites.1.2 Two methods are defined in this practice for the char-acterization of atmospheric test sites.The methods are identi-fied as characterization Methods A and B.The preferredcharacterization technique would require using both Method Aand B for concurrent data collection.1.2.1 Method A is to be used when atmospheric corrosion ismonitored on a continuing basis at a test site using specifiedmaterials and exposure configurations.1.2.2 Method B is specified when atmospheric factors aremonitored on a continuing basis.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A36/A36M Specification for Carbon Structural SteelB6 Specification for ZincG1 Practice for Preparing,Cleaning,and Evaluating Corro-sion Test SpecimensG50 Practice for Conducting Atmospheric Corrosion Testson MetalsG84 Practice for Measurement of Time-of-Wetness on Sur-faces Exposed to Wetting Conditions as in AtmosphericCorrosion TestingG91 Practice for Monitoring Atmospheric SO2DepositionRate for Atmospheric Corrosivity Evaluation3.Summary of Methods3.1 Characterization Method A is to be used when atmo-spheric corrosion data are to be obtained.3.1.1 Corrosion tests to measure the corrosivity of the testsite should follow the procedure established by Practice G50.Additional special instructions are identified in this procedurerelating to types of materials for corrosion characterizationtests,time of test exposure,positioning of test specimens,removal of test specimens and proper identification,cleaningpractices,and reporting of data.3.2 Characterization Method B is to be used when atmo-spheric climatological factors influencing the corrosion ofmetals are to be monitored.3.2.1 Several atmospheric factors which have been identi-fied as having significant bearing on the corrosion of metalsinclude,but are not limited to,sulfur dioxide,chlorides,temperature,humidity,precipitation,time of wetness,andatmospheric particulate matter.3.3 The preferred technique utilizes both Methods A and Bfor concurrent data to be collected.3.3.1 Should either Method A or B be singled out as theprimary technique to be used on a continuing basis,bothshould be used at some point in time to establish a data base.The availability of computerized weather stations greatlyfacilitates the collection of reliable atmospheric data.4.Significance and Use4.1 This practice gives suggested procedures for character-ization of atmospheric test sites.It can be useful to researchers,manufacturers,engineering firms,architects,and constructioncontractors to provide corrosion and environmental data,ma-terials selection information,and a materials storage practice.4.2 This practice does not give specific parameters forclassifying the type of test site.1This practice is under the jurisdiction of ASTM Committee G01 on Corrosionof Metals and is the direct responsibility of Subcommittee G01.04 on AtmosphericCorrosion.Current edition approved Nov.1,2015.Published December 2015.Last previousedition approved in 2010 as G9286(2010).DOI:10.1520/G0092-86R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 PROCEDURES5.Method A5.1 Materials:5.1.1 The materials recommended for conducting atmo-spheric corrosion characterization studies are copper-bearingstructural carbon steel(such as Specification A36/A36M with0.2%copper min)and high-purity zinc(Specification B6 highgrade).5.1.2 Materials recommended are the absolute minimumrequired to serve as a characterization base for test sites.Additional materials should be added to meet individual needs.Sufficient material shou